The Effect of Light Intensity and Nutrient Formula on the Growth of Chlorella ellipsoidea in Batch Cultivation

Abstract

In the aquaculture feed industry, the batch cultivation of the alga Chlorella ellipsoidea is frequent because it allows the control of factors contributing to product quality. In this study, we conducted batch-cultivation experiments in a smart algae cabinet with 4 different light intensities, 1,000, 3,000 and 5,000 Lux, as well as a fluorescent lamp (8,000 Lux). The growth curves, specific growth rate and biomass productivity of C. ellipsoidea provided with the BG-11, Bold and Chu-13 nutrient formulae were evaluated. The results revealed biomasses of 1.315 ± 0.0087, 1.042 ± 0.0063 and 1.096 ± 0.0036 g/L/day and specific growth rates of 0.979 ± 0.0067, 0.7453 ± 0.0060 and 0.7781 ± 0.0026 per day for the 3 formulae, BG-11, Bold and Chu-13, respectively. The mean biomasses of C. ellipsoidea grown on BG-11 at all light intensities were significantly higher than those for other media (p-value = 0.0001). With the log phase achieved in 3 days, BG-11 was more suitable for rearing at all tested light intensities, while Chu-13 was only applicable at 5,000 Lux. Using all 3 light intensities, it was possible to reduce the log-phase of algae growth from 7 to 3 days and increase biomass by more than 1.2 times when compared to fluorescent light culture. HIGHLIGHTS The batch cultivation was carried out in a smart algae cabinet that we are building and will publish soon. A smart algae network can control the factors that affect cultivation while also conducting all experiments at the same time. The 3 light intensities and BG-11 media used for cultivation in a smart algae cabinet can accelerate growth and biomass production. GRAPHICAL ABSTRACT